RAID is about availability, not backup. If the sites in question can stand a little down time, you might not need RAID at all. But you absolutely, positively want a backup solution, and maybe more than one. I have various personal bits of data I need to back up, but probably the most precious and least replaceable: family pictures. Those get backed up once a week to an online service, and once a month to a DVD, which then gets taken offsite (to my office).
A story I read: a guy had a RAID 1 system, but the primary disk started having issues, so the system silently reverted to the mirror. Mirror got updated with several months worth of data that were not mirrored to the primary. Then, again silently, the primary drive came back to life... and overwrote the contents of the mirrrored drive. Months worth of data... gone.
RAID is about availability, not backup. If the sites in question can stand a little down time, you might not need RAID at all. But you absolutely, positively want a backup solution, and maybe more than one. I have various personal bits of data I need to back up, but probably the most precious and least replaceable: family pictures. Those get backed up once a week to an online service, and once a month to a DVD, which then gets taken offsite (to my office).
A story I read: a guy had a RAID 1 system, but the primary disk started having issues, so the system silently reverted to the mirror. Mirror got updated with several months worth of data that were not mirrored to the primary. Then, again silently, the primary drive came back to life... and overwrote the contents of the mirrrored drive. Months worth of data... gone.